Chevy GM LS LS1 LS6 UnderDrive Fluid Damper Harmonic Balancer SFI 18.1 These Speedmaster crankshafts are made

These Speedmaster crankshafts are made from the same strong aircraft-quality forging as standard-weight cranks

They feature greater strength and durability

2 SFI Approved and will withstand the extreme power and rpm of your performance application

capable of withstanding valve spring load

as well as keep them in line

Chevy GM LS LS1 LS6 UnderDrive Fluid Damper Harmonic Balancer SFI 18.1 These Speedmaster crankshafts are madeUsing only three parts a laser welded sealed housing, an internal inertia ring, and highly viscous silicone fluid between the two these SFI approved Fluid dampers can control all crankshaft vibration, not just a limited frequency range. As a result, you get reduced wear on the main bearings and timing gear, more stable valvetrain operation, and less chance of crank failure.